CURT FAREWELL Mankell seems determined not only to end the Wallander series but to punish those readers who kept up the requests.

Henning Mankell has no respect for his readers. That's the only conclusion possible after finishing his latest, The Troubled Man, but it has been a long time coming. That this book puts an end to Mankell's long-time protagonist, detective Kurt Wallander, is only a small part of the problem.

Mankell, who splits his time between his native Sweden and Mozambique, made his name with nine smart police procedurals featuring the socially conscious, often depressed Wallander, who was recently brought to life for the BBC by Kenneth Branagh. In recent years, Mankell has also made headlines for his political action, as when he joined the flotilla seeking to break the Israeli blockade of Gaza. In his writing, as well, he has abandoned straight detective fiction for larger books with a political agenda. Although the aims of some of these — notably his bestselling, anti-globalization novel, The Man from Beijing (2007, released in the US in 2010) — may be noble, to expose the human cost of globalization, they have tended toward the preachy, and many of us loyal readers have long hoped he would return to the more subtle Wallanders. After all, books like The Dogs of Riga and Faceless Killers dealt obliquely with such issues as human trafficking. They were more artistically successful — and more fun.

Some of this mystery-world clamor must have reached Mankell, for after a break of about 10 years, he brought back the gloomy detective. (The previous Wallander book, the story collection The Pyramid, appeared in 1999, though it was not translated until 2008.) However, in this return, The Troubled Man, he seems determined not only to end the series but to punish those readers who kept up the requests.

The book begins with seemingly disconnected events. The prime minister is reading a report about foreign submarines in Swedish waters. The action then cuts to Wallander, who's contemplating his age (55) and grudgingly accepting an invitation from his daughter Linda to meet her live-in boyfriend's parents at a dinner party. The father, a former navy commander, is troubled, as the reluctant guest comes to see. And so when the father disappears, Wallander thinks back to that party for clues.

The ensuing mystery is, like many of Wallander's cases, complicated by government corruption. But this outing has a few extra twists. For starters, Wallander learns that a cherished former lover is terminally ill. More disturbing, the aging detective is having memory lapses. Wallander's father suffered from Alzheimer's; he died after a slow decline, following an idyllic father-son trip to Rome (recounted in The Fifth Woman), and so these near-blackouts are terrifying. This development also complicates the plot, forcing the veteran detective to rely on sudden inspiration rather than his usual deep insight into accumulating evidence. "And at that precise moment, as if the memory had opened a door for him, Wallander saw that he was totally on the wrong track," he realizes rather abruptly.

The ensuing breakthrough feels both hasty and didactic: political theory disguised as crime fiction. And then, as Wallander begins to return to normal life, he meets a truly horrifying fate, one that strips the detective of everything he holds dear. It's a sadistic ending, and not entirely in keeping with either Wallander's family history or medical fact.